The following questions refer to the description below. You have read that soapberry bugs,Jadera haematoloma,adapt to available food sources.For example,in southern Florida,soapberry bugs feed on seeds of a native plant,the balloon vine.In central Florida,the balloon vine is rare and soapberry bugs have switched to eating seeds of an introduced species,the goldenrain tree.The seeds of the goldenrain tree fruits are much closer to the fruit surface than the seeds of the native balloon vine fruit.As a result,natural selection results in beaks that are shorter in soapberry bugs that utilize goldenrain tree fruits than those that feed on balloon vine fruit seeds. -Within six months of effectively using methicillin to treat S.aureus infections in a community,all new infections were caused by MRSA.How can this result best be explained?
A)S) aureus can resist vaccines. B)A patient must have become infected with MRSA from another community. C)In response to the drug, S. aureus began making drug-resistant versions of the protein targeted by the drug. D)Some drug-resistant bacteria were present at the start of treatment, and natural selection increased their frequency. E)The drug caused the S. aureus DNA to change.